The Bank for International Settlements (BIS) and the central banks of France, Singapore, and Switzerland completed a joint test of wholesale central bank digital currencies (CBDCs) cross-border trading and settlement.

Under the auspices of the BIS, the Banque de France, the Monetary Authority of Singapore, and the Swiss National Bank created Project Mariana. It has tested cross-border trading and settlement of hypothetical euro, Singapore dollar, and Swiss franc CBDCs between simulated financial institutions on a public blockchain using decentralized finance (DeFi) technological concepts.

The concept operates by utilizing a single token standard on a public blockchain, bridges for the seamless movement of CBDCs between networks, and a specific sort of decentralized exchange to automatically trade and settle spot foreign currency transactions.

The participants consider the trial a success, however "further research and experimentation is needed" according to the announcement. It also expresses reservations about Project Mariana's experimental nature, stating:

“Project Mariana is purely experimental and does not indicate that any of the partner central banks intend to issue CBDC or endorse DeFi or a particular technological solution.”

The day before the public release of Project Mariana, BIS general manager Agustn Carstens remarked about the importance of clarifying national legal frameworks in countries where central banks do not have the authority to issue CBDC.

The BIS is the primary proponent of cross-border CBDCs, with various pilot tests underway around the world. Thus, the central banks of Hong Kong and Israel presented Project Sela results in September, while Hong Kong Monetary Authority CEO Eddie Yue announced the expansion of Project mBridge, which has already included the central banks of China, Thailand, and the United Arab Emirates.

Sources:

https://cointelegraph.com/news/cbdc-bis-france-singapore-switzerland-test

https://www.banque-france.fr/en/communique-de-presse/bis-and-central-banks-france-singapore-and-switzerland-successfully-test-cross-border-wholesale